I. Field
The present invention relates generally to communication, and more specifically to techniques for transmitting signaling and data after reconfiguration of a physical layer in a wireless communication system.
II. Background
Wireless communication systems are widely deployed to provide various types of services such as voice, packet data, and so on. These systems may be multiple-access systems capable of supporting communication for multiple users, and may be based on Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), or some other multiple access techniques. CDMA systems may provide certain advantages over other types of system such as increased system capacity.
A CDMA system may implement one or more commonly known CDMA standards such as Wideband-CDMA (W-CDMA), IS-2000, IS-856, IS-95, and so on. W-CDMA and IS-2000 are third generation CDMA standards with advanced capabilities and services. To conserve system resources, a wireless device (e.g., a cellular phone) in a third generation CDMA system is typically allocated sufficient system resources based on its requirements, which may in turn be dependent on the amount of activity at the wireless device. The allocated system resources may be defined by one or more physical channels used for data and signaling transmission, a specified rate for each physical channel, and so on. Additional or less system resources may be allocated to the wireless device whenever the amount of activity changes.
A reconfiguration process is typically performed between the CDMA system and the wireless device to effectuate a change in the allocation of system resources to the wireless device. The reconfiguration process is specified by the particular CDMA standard being implemented by the CDMA system and typically affects the physical layer (and possibly other layers). For example, in W-CDMA, the system and wireless device each perform a respective set of tasks for the reconfiguration process. The system and wireless device may require different amounts of time to complete the required tasks for the reconfiguration process. As a result, there exists a period of uncertainty during which the wireless device does not know whether the system has completed the reconfiguration process, and vice versa. If the wireless device transmits data during this uncertainty period, there is a high degree of likelihood that the data transmission will not be decoded correctly by the system. A failed data transmission wastes system resources, consumes battery power, and causes interference that degrades performance for other wireless devices, all of which are undesirable.
There is therefore a need in the art for techniques to efficiently transmit signaling and data after reconfiguration in a CDMA system.